Hydrocracking catalyst, producing method thereof, and hydrocracking method

ABSTRACT

A hydrocracking catalyst has a carrier that has particles of a compound oxide and a binder present between these particles, and at least one metal component selected from Group 6, Group 9 or Group 10 of the Periodic Table supported on the carrier. The catalyst has a median pore diameter of 40 to 100 Å and the volume of pores whose pore diameter falls within a range of 40 to 100 Å is at least 0.1 mL/g. Moreover, the volume of pores of the catalyst whose pore diameter falls within a range of 0.05 to 5 μm is 0.05 to 0.5 mL/g, and the volume of pores whose pore diameter is 0.5 to 10 μm is less than 0.05 mL/g. This catalyst is mechanically strong enough for practical use and has a high conversion rate and middle distillate selectivity in hydrocracking of hydrocarbon oils, particularly vacuum gas oil.

This application is the national phase under 35 U.S.C. §371 of PCTInternational Application No. PCT/JP99/04722 which has an Internationalfiling date of Aug. 31, 1999, which designated the United States ofAmerica.

TECHNICAL FIELD

The present invention relates to a method of hydrocracking ofhydrocarbon oils, and a catalyst that is suitable for hydrocracking ofhydrocarbon oils and a method of its production. The present inventionparticularly relates to a method of hydrocracking with which the vacuumgas oil fractions can be efficiently converted to light gas oil byhydrocracking, as well as a catalyst that is suitable for hydrocrackingof the vacuum gas oil fractions and a method of its production.

BACKGROUND ART

The demand for oil has recently shifted toward gas oils. Althoughgasoline and naphtha can be mass-produced by fluidized catalyticcracking, kerosene, gas oil, jet fuel, etc., which are referred to asmiddle distillates, of preferred quality are not obtained by fluidizedcatalytic cracking. Therefore, the method of hydrocracking of vacuum gasoil is often used for mass-production of high-quality middle distillatesin the oil refining industry.

Although the desired fraction can be obtained by bringing the crude oiland catalyst into contact at a high temperature in the presence ofhydrogen under high pressure in the field of hydrocracking of vacuum gasoil, selection of the reaction conditions and catalyst for this isimportant. For example, more severe reaction conditions or a catalyst ofa hydrogenation active metal species supported on a carrier with ahigher content of solid, strongly acidic zeolite can be used in order toimprove the conversion rate. Nevertheless, when a reaction is performedusing this type of catalyst, there is a disadvantage in that althoughthe conversion rate is increased, large quantities of gas and naphthaare produced and selectivity of the middle distillates therefore ispoor.

Therefore, taking into consideration diffusibility of the hydrocarbonmolecules that will react, attention is given to the fine poredistribution of the catalyst in designs of catalysts that efficientlyproduce middle distillate (Julius Scherzer, A. J. Gruia, ‘HydrocrackingScience and Technology,’ Mercel Dekker, Inc., New York, 1996). Forinstance, Japanese Patent Application Laid Open No. 06-190278 disclosesthat a hydrocracking catalyst of a hydrogenation active metal supportedon a carrier consisting of boria, silica, and alumina with an averagepore diameter of 90 to 120 Å is suitable for obtaining high middledistillate selectivity. Thus, improving middle distillate selectivity bytaking into consideration the pore diameter distribution of so-calledmesopores is a technology that is known in this field.

On the other hand, hydrocracking catalysts that are packed in fixed bedreactors and used industrially are usually shaped into cylinders orspheres. Technology where there are so-called macropores of 0.05 μm orlarger present in this type of shaped catalyst is also known. Forexample, Japanese Patent Publication No. 05-36099 discloses a catalystobtained by supporting hydrogenation active component on a carrierconsisting of an alumna inorganic oxide and zeolite in order tohydrogenate mainly heavy hydrocarbons such as atmospheric residue. ThisJapanese Patent Application Laid Open discloses the fact that becausethis catalyst has macropores with a pore diameter of 600 Å or larger at0.1 mL/g or more, deposition of carbonaceous matter and metal impuritiesand plugging of pores caused by the deposition can be prevented and as aresult, yield of the kerosene and gas oil is improved.

Nevertheless, in general, shaped catalysts with macropores generallyhave a disadvantage in that their mechanical strength is weak becauseporosity is high (Takabo Shirozaki, Takayuki Todo, editors, “CatalystPreparation,” Kodansha, 1974) and therefore, the problem easily developswhere the catalyst is broken down and crushed when catalyst is producedand packed in the reactor or during the reaction.

To the inventors' knowledge, there is still no technology whereby ahydrocracking catalyst is simultaneously given a specific mesoporediameter distribution and a specific macropore diameter distribution andthe hydrocracking catalyst is used for hydrocracking of hydrocarbonoils, preferably demetalized hydrocarbon oils that mainly containfractions with boiling points which is higher than a predeterminedboiling point, particularly vacuum gas oil or heavy gas oil.

DISCLOSURE OF THE INVENTION

The purpose of the present invention is to provide a new hydrocrackingcatalyst with a high conversion rate and middle distillate selectivityin hydrocracking of hydrocarbon oils, particularly vacuum gas oil andheavy gas oil, and practical mechanical strength, and to provide amethod of producing this catalyst as well as a method of hydrocrackingusing this hydrocracking catalyst.

The hydrocracking catalyst of the present invention is provided, whichcomprises a catalyst carrier having particles of a compound oxide and abinder component present between these particles, and at least one metalcomponent selected from Group 6(VI), Group 9(IX) and Group 10(X) of thePeriodic Table, wherein

(A) the median pore diameter of the catalyst is 40 to 100 Å and thevolume of pores whose pore diameter is within a range of 40 to 100 Å isat least 0.1 mL/g and

(B) the volume of pores whose pore diameter is within a range of 0.05 to0.5 μm of the catalyst is 0.05 to 0.5 mL/g and the volume of pores witha pore diameter of 0.5 to 10 μm is less than 0.05 mL/g.

The compound oxide is preferably made up of one or more selected fromsilica-alumina, silica-titania, silica-zirconia, silica-magnesia,silica-alumina-titania, and silica-alumina-zirconia. Also, the compoundoxide is preferably made up of one or more selected from silica-alumina,silica-titania, silica-zirconia, silica-magnesia,silica-alumina-titania, and silica-alumina-zirconia; and USY zeolite.

Moreover, the binder component is made from alumina and/orboria-alumina, and the metal component is preferably one or more ofmolybdenum, tungsten, cobalt, rhodium, iridium, nickel, palladium, andplatinum, and furthermore, it is preferred that at least 60% of thecompound oxide particles have a diameter of 10 μm or smaller.

The method of producing a hydrocracking catalyst (hydrocracking catalystcomposition) of the present invention comprises the steps of mixingcompound oxide powder comprising at least 60% powder with a particlediameter of 10 μm or smaller and binder component; shaping, drying andfiring the mixture to form the carrier; and supporting at least onemetal component selected from Group 6, Group 9 and Group 10 of thePeriodic Table on the carrier, and thereby obtaining a hydrocrackingcatalyst wherein (A) median pore diameter is 40 to 100 Å and the volumeof pores whose pore diameter is within a range of 40 to 100 Å is atleast 0.1 mL/g and (B) volume of pores whose pore diameter is within arange of 0.05 to 0.5 μm is 0.05 to 0.5 mL/g and volume of pores with apore diameter of 0.5 to 10 μm is less than 0.05 mL/g.

By means of the above-mentioned production method, the binder componentis made from one or more selected from hydrated aluminium oxide orboria-containing hydrated aluminium oxide.

The method of hydrocracking hydrocarbon oils in accordance with thepresent invention is a method with which hydrocarbon oils can beconverted to a product in which the fraction with a relatively highboiling point contained in this hydrocarbon oil has been reduced bybringing the hydrocarbon oil into contact with the above-mentionedhydrocracking catalyst of the present invention in the presence ofhydrogen.

BRIEF DESCRIPTION OF THE INVENTION

FIG. 1 is a graph showing pore diameter distribution of a hydrocrackingcatalyst made by the examples and comparative examples of the presentinvention. A and B in the graph show pore diameter distribution ofcatalysts A and B produced by the examples, and E shows pore diameterdistribution of catalyst E made by the comparative example. The verticaland horizontal axes of the graph indicate dV/d(log D) and D,respectively, wherein V is pore volume and D is pore diameter.

BESTMODE FOR CARRYING OUT THE INVENTION

The details of the hydrocracking catalyst and hydrocracking method ofthe present invention will be described below based on the poreproperties of the catalyst, the structural materials of the catalyst,the method of producing the catalyst and the hydrocracking reaction,etc.

[Pore Properties of the Hydrocracking Catalyst]

The hydrocracking catalyst of the present invention is characterized inthat it has pore properties that satisfy both conditions (A) and (B)below:

(A) the median pore diameter of the catalyst is 40 to 100 Å and thevolume of pores whose pore diameter is within a range of 40 to 100 Å isat least 0.1 mL/g and

(B) the volume of pores whose pore diameter is within a range of 0.05 to0.5 μm of this catalyst is 0.05 to 0.5 mL/g and the volume of pores witha pore diameter of 0.5 to 10 μm is less than 0.05 mL/g.

The so-called mesopore properties, that is, pore properties pertainingto above-mentioned condition (A), are determined by the nitrogen gasadsorption method and the correlation between pore volume and porediameter can be calculated by the BJH method, etc. Moreover, median porediameter is the pore diameter where cumulative pore volume from the sidewhere pore diameter is larger becomes V/2 when pore volume obtainedunder conditions of a relative pressure of 0.9667 by the nitrogen gasadsorption method is V. The median pore diameter of the hydrocrackingcatalyst is within a range of 40 to 100 Å, and further, a median porediameter within a range of 45 to 90 Å, particularly, a median porediameter within a range of 50 to 85 Å, is preferred. The volume of poreswhose pore diameter is within a range of 40 to 100 Å is at least 0.1mL/g, and this pore volume is preferably 0.1 to 1.0 mL/g, particularly0.15 to 0.6 mL/g.

The above-mentioned mesopore properties of the hydrocracking catalystcan be obtained basically by controlling the pore diameter of thecompound oxide to have such mesopore properties, because the mesoporeproperties of the compound oxide is usually maintained until thecatalyst is made by the compound oxide.

So-called macropore properties, that is, the pore properties related toabove-mentioned condition (B), can be determined using the mercuryintrusion porosimetry and can be calculated assuming that the angle ofcontact of mercury is 140°, surface tension is 480 dynes/cm, and thatall of the pores have cylindrical shape. A hydrocracking catalyst wherethe volume of pores with a diameter of 0.05 to 1 μm is 0.05 to 0.5 mL/gand the volume of pores with a diameter of 1 μm or larger is less than0.05 mL/g is used. It is further preferred that the volume of pores witha diameter of 0.05 to 0.5 μm be 0.04 to 0.5 mL/g, particularly 0.05 to0.5 mL/g, and that the volume of pores with a diameter of 1 μm or largerbe less than 0.05 mL/g, further, less than 0.02 mL/g, particularly 0.01mL/g because mechanical strength of the catalyst will be increased.

The macropore properties can be controlled by voids formed between thecompound oxide particles and a loading rate of the voids with a binder.The voids formed between the compound oxide particles are controlled bythe diameters of the compound oxide particles. The loading rate iscontrolled by mixing ratio or weight ratio of the binder and thecompound oxide, which will be described later.

The mesopore and macropore properties may also be influenced by thecharacteristic of the binder and a condition of kneading process whichwill be described later.

[Compound Oxide]

The compound oxide used in the present invention is a compound oxidewith solid acidity. Several of these compound oxides are known,beginning with the 2-element compound oxides confirmed to be acidic byK. Shibata, T., Kiyoura, J. Kitagawa, K. Tanabe, Bull. Chem. Soc. Jpn.,46, 2985 (1973), but silica-alumina, silica-titania, silica-zirconia andsilica-magnesia are preferably used. Silica-alumina-titania andsilica-alumina-zirconia are preferably used as the 3-element compoundoxides. In addition, the compound oxide of the present invention canalso contain zeolite, such as USY zeolite, etc.

USY zeolite is ultra-stable Y zeolite. It is Y zeolite characterized byits alkali metal ion content of under 4 wt %, preferably under 1 wt %,its lattice constant of less than 24.50 Å, and its silica (SiO₂)/alumina(Al₂O₃) molar ratio of 5 or higher.

In case that a powder form of compound oxide other than USY zeolite isused as the starting material for producing a hydrocracking catalyst,the pore properties of the hydrocracking catalyst of the presentinvention are easily obtained when the volume of pores with a porediameter within a range of 40 to 100 Å is at least 0.1 mL/g and medianpore diameter is within a range of 35 to 100 Å. A powder with a medianpore diameter within a range of 40 to 90 Å is further preferred, and onewith a median pore diameter within a range of 45 to 85 Å is particularlypreferred. Moreover, as long as the above-mentioned pore properties aresatisfied, a compound oxide powder with a larger relative surface areais preferred. Basically, a powder specific surface area of 250 m²/g orlarger is preferred, 300 m²/g or larger is further preferred, and 350m²/g or larger is particularly suitable.

When the compound oxide of the present invention is used in powder form,it is preferred that a compound oxide at least 60% of which is particleaggregates with a diameter of 10 μm or less be used because themacropore properties of the present invention can be easily obtained anda catalyst with sufficient mechanical strength will be easily obtained.If a powder of 2 or more compound oxides is used, overall, at least 60%of the powder should be particle aggregates with a diameter of 10 μm orsmaller, and 60% or more, particularly 70% or more, preferably has adiameter of 1 to 10 μm. Particle diameter of the particle aggregates canbe determined by the method whereby the particle groups dispersed inwater are irradiated with laser light and diameter is found from thisscattered light. Moreover, a compound oxide powder that has beenpre-treated by dry crushing or wet crushing to bring the percentage ofparticle aggregates with a diameter of 10 μm or smaller to at least 60%can also be used. Compound oxide is present as particles with almost thesame size as the size of the particle aggregates in the catalyst usingparticle aggregates of compound oxide.

[Binder Component]

The binder component used by the present invention should be made fromalumina and/or boria-alumina. The alumina here is aluminum oxide,aluminum hydroxide and/or hydrated aluminium oxide. The boria-alumina isaluminum oxide, aluminum hydroxide and/or boria-containing hydratedaluminum oxide. The boria-alumina can also include boria as a mixture,and it can be comprised as a solid-solution or a combined compound.

The binder component that is a starting material of the carrier ispreferably a powder consisting of aluminum hydroxide and/or hydratedaluminium oxide (referred to below simply as alumina powder),particularly hydrated aluminium oxide with a boehmite structure, such aspseudo-boehmite, etc., because when this is used, hydrocracking activityand middle distillate selectivity can be improved. Moreover, it ispreferred that the binder component be a powder that consists ofaluminum hydroxide or boria-containing hydrated aluminium oxide(referred to below simply as boria-alumina powder), particularlyhydrated aluminium oxide with a boehmite structure, such aspseudo-boehmite, including boria because hydrocracking activity andmiddle distillate selectivity will be improved.

The weight of the binder component is preferably 5 to 50 wt %,particularly 15 to 35 wt %, of the total weight of compound oxidecomponent and binder component making up the catalyst. If it is lessthan this range, there will be a reduction in mechanical strength of thecatalyst, and when it exceeds this range, there will be a relativereduction in hydrocracking activity and in middle distillateselectivity. When USY zeolite is used as the compound oxide, the weightof USY zeolite component is preferably 0.1 to 30 wt %, particularly 0.2to 20 wt %, of the total weight of the compound oxide component and thebinder component making up the catalyst. If it is less than this range,it will be difficult to realize improvement of hydrocracking activitywith the use of USY zeolite, and if it exceeds this range, there will bea relative drop in middle distillate selectivity. When silica-alumina isused as the compound oxide, the weight of alumina is 10-60 wt % ofsilica-alumina or molar ratio of silica/alumina is 1-20.

[Metal Component]

The hydrocracking catalyst of the present invention comprises one ormore metal components selected from Group 6, Group 9 and Group 10 of thePeriodic Table. Molybdenum, tungsten, cobalt, rhodium, iridium, nickel,platinum, and palladium are particularly suitable as the metal selectedfrom Group 6, Group 9, and Group 10 of the Periodic Table used in thecatalyst of the present invention. These metals can be used as onecomponent or a mixture of 2 or more components. These metals arepreferably added so that the total amount of Group 6, Group 9 or Group10 metal contained in the hydrocracking catalyst is 0.05 to 35 wt %,particularly 0.1 to 30 wt %. When molybdenum is used as the metal, theamount added is preferably 5 to 20 wt % of the hydrocracking catalyst.When tungsten is used, the amount added is preferably 5 to 30 wt % ofthe hydrocracking catalyst. If the amount of molybdenum or tungsten isless than the above-mentioned range, hydrogenation capability of theactive metal necessary for hydrocracking will be insufficient and thistherefore is not preferred. On the other hand, if the amount added isoutside the above-mentioned range, aggregation of the active metalcomponent that has been added will easily occur and this therefore isnot preferred. It is further preferred that cobalt or nickel be addedwhen molybdenum or tungsten are used as the metal because hydrogenationcapability of the active metal will improve. The total amount of cobaltor nickel added in this case is preferably 0.5 to 10 wt % of thehydrocracking catalyst. When one or more of rhodium, iridium, platinum,and palladium is used as the metal, the amount added is preferably 0.1to 5 wt %. If it is less than this amount, this is not preferred becausesufficient hydrogenation capability will not be obtained and exceedingthis range is uneconomic.

[Preparing the Hydrocracking Catalyst]

The ratio of the total of the number of moles of elements other thanaluminum in terms of oxide (for instance, number of moles of SiO₂, TiO₂,ZrO₂, and MgO) and the number of moles in terms of oxide of aluminum(number of moles of Al₂O₃) in compositions of elements other than metalelements of Group 6, Group 9, and Group 10 and boron, carbon, hydrogen,nitrogen and oxygen in the hydrocracking catalyst of the presentinvention is preferably within a range of 0.5 to 10, further, within arange of 0.7 to 7. A ratio less than this range or exceeding this rangeis not preferred because there will be a reduction in hydrocrackingactivity, middle distillate selectivity and catalyst mechanicalstrength.

[Method of Producing Hydrocracking Catalyst]

The catalyst that is made in this way can be obtained by kneading andshaping the compound oxide powder and binder component and drying andfiring (baking) to obtain the carrier and further impregnating andsupporting the metal component and then drying and firing. However,another method can be used as long as a catalyst with the desired poreproperties can be made.

A kneading machine generally used for catalyst preparation can be usedfor kneading. The method whereby the starting materials are introducedand water is added and the contents are mixed with mixing blades isusually preferred, but there are no particular limitations to the orderin which the starting materials and additives are introduced, etc.Ordinary water is used for kneading, and it is not particularlynecessary to add water when the starting materials are in slurry form.Moreover, the liquid that is added can also be an organic solvent suchas ethanol, isopropanol, acetone, methyl ethyl ketone, methyl isobutylketone, etc. The temperature during kneading and kneading time vary withthe compound oxide and binder component used as the starting materials,and there are no special limitations as long as they are conditionsunder which the desired pore structure is obtained. Similarly, as longas it is within a range with which the properties of the catalyst of thepresent invention are retained, it is possible to add and knead an acidsuch as sulfuric acid, a base such as ammonia, an organic compound suchas citric acid or ethylene glycol, a water-soluble polymer compound suchas cellulose ether or polyvinyl alcohol, ceramic fibers, etc.

Shaping after kneading can be performed using shaping methods generallyused for catalyst preparation. It is preferred that shaping be performedby extrusion shaping with a screw extruder, etc., with which any shape,such as pellets, etc., can be efficiently shaped, or by the oil dropmethod with which shaping into spherical shape can be efficientlyaccomplished. There are no special limitations to the size of the shapedarticle, but when it is, for instance, cylindrical pellets, pellets thathave a diameter of 0.5 to 20 mm and a length of 0.5 to 15 mm can usuallybe easily obtained.

The shaped article obtained as previously described is dried and firedto produce the carrier. This firing treatment is preferably firing for0.1 to 20 hours at a temperature of 300 to 900° C. in air or a gasatmosphere such as nitrogen, etc.

There are no special limitations to the method of supporting metalcomponent on the carrier and impregnation methods by spraying orimmersion, etc., ion exchange methods, etc., are suitable. Moreover,more metal component can be supported by repeating the support treatmentand drying treatment. It is preferred that the hydrocracking catalyst ofmetal component supported on a carrier be fired for 0.1 to 20 hours at atemperature of 300 to 900° C. in air or a gas atmosphere such asnitrogen because activity of the catalyst will be increased.

[Mechanical Strength of Hydrocracking Catalyst and Carrier]

Mechanical strength of the hydrocracking catalyst in terms of the edge(side) collapsing strength of cylindrical pellets with a diameter of 1.6mm is 3 kg or higher, preferably 4 kg or higher. Moreover, when acatalyst is made by supporting the metal component by impregnation oncethe carrier has been made by shaping, it is preferred that the shapedcarrier have sufficient mechanical strength to obtain a catalyst withgood yield, and mechanical strength of the shaped carrier of the presentinvention is 3 kg or stronger, preferably 4 kg or stronger, in terms ofside crushing strength of cylindrical pellets with a diameter of 1.6 mm.

[Hydrocracking Method]

The method of hydrocracking hydrocarbon oils by the present invention isa method whereby hydrocarbon oil is brought into contact with theabove-mentioned type of catalyst in the presence of hydrogen when thestarting hydrocarbon oil is converted to a product in which thefractions with a relatively high boiling point, or the fractions with aboiling point above a specific temperature, contained in thishydrocarbon oil are reduced.

There are no special limitations to the hydrocarbon oil that can be usedas the starting material, but one containing 80 wt % or more fractionswith a boiling point of 250° C. or higher is preferably used. There areno special limitations to the source of the hydrocarbon oil that can beused as the starting material, but oils derived from crude oil, coalliquefaction oil, oil shell, oil sand, etc., and Fischer-Tropschsynthetic oil, etc., are preferably used. The hydrocarbon oil that isused as the starting material may comprise impurities other thanhydrocarbons, but a lower impurity content is preferred, and it ispreferred that hydrocarbon oil that has been pre-treated byhydrotreating, such as desulfurization, denitrification, anddemetalization, and by deasphalting be used. Materials with which theoriginal pore diameter can be retained because metal substances do notdeposit in the mesopore and macropores are particularly preferred.Actually, a starting oil with both a vanadium content and nickel contentof 0.0005 wt % or less, preferably 0.0002 wt %, more preferably 0.0001wt %, is suitable.

By means of the method of hydrocracking hydrocarbon oils of the presentinvention, the starting hydrocarbon oil is converted to a product withwhich the fractions having a boiling point higher than a specifictemperature are reduced, and this specific temperature can be selectedfrom any temperature in accordance with the desired product. It ispreferred that a temperature of 180° C. to 400° C. be selected.Moreover, the hydrocarbon oil used as the starting material should beselected so that it contains 50 wt % or more, preferably 80 wt % ormore, particularly 90 wt % or more, of fraction with a boiling pointthat is above the specific temperature selected here.

By means of the method of hydrocracking of hydrocarbon oils of thepresent invention, catalyst is packed into the reaction vessel and thenpre-treated by drying, reduction, sulfiding, etc., and used. It isparticularly preferred that sulfiding treatment be performed before thecatalyst is used in hydrocracking when it comprises an element of Group6 as the metal component.

By means of the method of hydrocracking a hydrocarbon oil of the presentinvention, hydrocracking is performed in the presence of hydrogen, andit is preferred that this be performed under increased pressure so thatoverall pressure is 2 MPa to 30 MPa. The liquid hourly space velocity(LHSV) used for hydrocracking of hydrocarbon oils by the presentinvention is 0.2 h⁻¹ to 5.0 h⁻¹, particularly 0.3 h⁻¹ to 3.0 h⁻¹. Thehydrogen/starting oil feed ratio suitable for hydrocracking ofhydrocarbon oil by the present invention is 100 NL/L to 5,000 NL/L. Bymeans of the method of hydrocracking hydrocarbon oil by the presentinvention, the reaction should be performed at a temperature of 250° C.to 500° C., particularly 300° C. to 450° C.

EXAMPLES

The catalyst and method of its production, as well as hydrocrackingmethod, of the present invention will now be explained in detail withworking examples and comparative examples.

[Catalyst A]

As will be described below, catalyst A consisting of 11.0 wt % W, 1.0 wt% Ni, 67.9 wt % silica-alumina, and 17.0 wt % alumina was prepared.

First, 1,136 g silica-alumina powder (silica/alumina molar ratio of 7.4,93.4 wt % of which was powder of particle aggregates with a diameter of1 to 10 μm, ignition loss of 16.4 wt %) and 325 g pseudo-boehmite powder(ignition loss of 27.0 wt %) were kneaded while being mixed, and shapedinto a cylindrical shape by extrusion from a round opening with adiameter of 1.6 mm. Then a carrier of a silica-alumina/alumina mixturewas prepared by drying this shaped article for 15 hours at 130° C. andthen firing for 1 hour at 600° C. under an air flow. The mean edgecollapsing strength of this carrier was 6.3 kg.

The carrier was impregnated by spraying with an aqueous ammoniummetatungstate solution and dried for 15 hours at 130° C. Then it wasimpregnated by spraying with an aqueous nickel nitrate solution anddried for 15 hours at 130° C. Next, it was fired for 30 minutes at 500°C. under an air flow. Catalyst A was thereby obtained.

When the pore properties of this catalyst A were measured by nitrogengas adsorption, the volume of pores with a pore diameter within a rangeof 40 to 100 Å was 0.328 mL/g and the median pore diameter was 51 Å.Moreover, as a result of determining pore properties of catalyst A bymercury intrusion porosimetry, the volume of pores with a pore diameterwithin a range of 0.05 to 0.5 μm was 0.085 mL/g, and the volume of poreswith a pore diameter of 0.5 μm to 10 μm was 0.001 mL/g. Furthermore, thevolume of pores with a pore diameter within a range of 0.05 to 1 μm was0.086 mL/g, and the volume of pores with a pore diameter within a rangeof 1 to 10 μm was less than 0.001 mL/g.

The pore properties of catalyst A are shown by line A in FIG. 1. Thereis a sharp peak within the range of a pore diameter of 40 to 100 Å(mesopores), and there is also an obvious peak within a range of 0.05 to0.5 μm (macropores).

In addition, mean side crushing strength of this catalyst A was 5.9 kg.

[Catalyst B]

As will be described below, catalyst B consisting of 16.5 wt % W, 1.5 wt% Ni, 61.1 wt % silica-alumina, 0.8 wt % USY zeolite, and 15.5 wt %alumina was prepared.

First, 1,372 g silica-alumina powder (silica/alumina molar ratio of 4.4,94.4 wt % of which was powder of particle aggregates with a diameter of1 to 10 μm, ignition loss of 16.9 wt %), 16.1 g USY zeolite(silica/alumina molar ratio of 30.3, Na content of 0.02 wt %, latticeconstant of 24.29 Å, 67.9 wt % of which was particle aggregates with adiameter of 1 to 10 μm, ignition loss of 10.6 wt %), and 395 gpseudo-boehmite powder (ignition loss of 27.0 wt %) were kneaded whilebeing mixed, and shaped into a cylindrical shape by extrusion from around opening with a diameter of 1.6 mm. Then a carrier of asilica-alumina/USY zeolite/alumina mixture was prepared by drying thisshaped article for 15 hours at 130° C. and firing for 1 hour at 600° C.under an air flow. The mean side crushing strength of this carrier was4.0 kg.

The carrier was impregnated by spraying with an aqueous ammoniummetatungstate solution and dried for 15 hours at 130° C. Then it wasimpregnated by spraying with an aqueous nickel nitrate solution anddried for 15 hours at 130° C. Next, it was fired for 30 minutes at 500°C. under an air flow. Catalyst B was thereby obtained.

When the pore properties of this catalyst B were measured by nitrogengas adsorption, the volume of pores with a pore diameter within a rangeof 40 to 100 Å was 0.279 mL/g and the median pore diameter was 52 Å.Moreover, as a result of determining pore properties of catalyst B bymercury intrusion porosimetry, the volume of pores with a pore diameterwithin a range of 0.05 to 0.5 μm or larger was 0.101 mL/g, and thevolume of pores with a pore diameter of 0.5 μm to 10 μm was 0.004 mL/g.Furthermore, the volume of pores with a pore diameter within a range of0.05 to 1 μm was 0.104 mL/g, and the volume of pores with a porediameter of 1 μm to 10 μm was 0.001 mL/g.

The pore properties of catalyst B are shown by line B in FIG. 1. As withcatalyst A, there is a sharp peak within the range of a pore diameter of40 to 100 Å (mesopores), and there is also an obvious peak within a porediameter range of 0.05 to 0.5 μm (macropores).

In addition, mean side crushing strength of this catalyst A was 4.4 kg.

[Catalyst C]

As will be described below, catalyst C consisting of 22.0 wt % W, 2.0 wt% Ni, 50.9 wt % silica-alumina, 4.9 wt % USY zeolite, and 13.9 wt %boria-alumina was prepared.

First, 1,136 g silica-alumina powder (silica/alumina molar ratio of 7.4,93.4 wt % of which was powder of particle aggregates with a diameter of1 to 10 μm, ignition loss of 16.4 wt %), 102 g USY zeolite(silica/alumina molar ratio of 30.3, Na content of 0.02 wt %, latticeconstant of 24.29 Å, 67.9 wt % of which was particle aggregates with adiameter of 1 to 10 μm, ignition loss of 10.6 wt %), and 324 gboria-alumina powder (boron content of 2.6 wt %, ignition loss of 19.7wt %) were kneaded and mixed and shaped into a cylindrical shape byextrusion from a round opening with a diameter of 1.6 mm. Then a carrierof a silica-alumina/USY zeolite/boria-alumina mixture was prepared bydrying this shaped article for 15 hours at 130° C. and firing for 1 hourat 600° C. under an air flow. The mean side crushing strength of thiscarrier was 6.6 kg.

The carrier was impregnated by spraying with an aqueous ammoniummetatungstate solution and dried for 15 hours at 130° C. Then it wasimpregnated by spraying with an aqueous nickel nitrate solution anddried for 15 hours at 130° C. Next, it was fired for 30 minutes at 500°C. under an air flow. Catalyst C was thereby obtained.

When the pore properties of this catalyst C were measured by nitrogengas adsorption, the volume of pores with a pore diameter within a rangeof 40 to 100 Å was 0.194 mL/g and the median pore diameter was 69 Å.Moreover, as a result of determining pore properties of catalyst C bymercury intrusion porosimetry, the volume of pores with a pore diameterwithin a range of 0.05 to 0.5 μm was 0.076 mL/g, and the volume of poreswith a pore diameter of 0.5 μm to 10 μm was 0.001 mL/g. Mean sidecrushing strength of this catalyst C was 8.4 kg.

[Catalyst D]

As will be described below, catalyst D consisting of 22.0 wt % W, 2.0 wt% Ni, 53.3 wt % silica-alumina, 2.4 wt % USY zeolite, and 13.9 wt %alumina was prepared.

First, 1,143 g silica-alumina powder (silica/alumina molar ratio of 4.4,94.4 wt % of which was powder of particle aggregates with a diameter of1 to 10 μm, ignition loss of 16.9 wt %), 49 g USY zeolite(silica/alumina molar ratio of 30.3, Na content of 0.02 wt %, latticeconstant of 24.29 Å, 67.9 wt % of which was particle aggregates with adiameter of 1 to 10 μm, ignition loss of 10.6 wt %), and 340 gpseudo-boehmite powder (ignition loss of 27.0 wt %) were kneaded whilebeing mixed, and shaped into a cylindrical shape by extrusion from around opening with a diameter of 1.6 mm. Then a carrier of asilica-alumina/USY zeolite/alumina mixture was prepared by drying thisshaped article for 15 hours at 130° C. and firing for 1 hour at 600° C.under an air flow. The mean side crushing strength of this carrier was4.0 kg.

The carrier was impregnated by spraying with an aqueous ammoniummetatungstate solution and dried for 15 hours at 130° C. Then it wasimpregnated by spraying with an aqueous nickel nitrate solution anddried for 15 hours at 130° C. Next, it was fired for 30 minutes at 500°C. under an air flow. Catalyst D was thereby obtained.

When the pore properties of this catalyst D were measured by nitrogengas adsorption, the volume of pores with a pore diameter within a rangeof 40 to 100 Å was 0.231 mL/g and the median pore diameter was 52 Å.Moreover, as a result of determining pore properties of catalyst D bymercury intrusion porosimetry, the volume of pores with a pore diameterwithin a range of 0.05 to 0.5 μm was 0.070 mL/g, and the volume of poreswith a pore diameter of 0.5 μm to 10 μm or larger was 0.003 mL/g.Furthermore, the volume of pores with a pore diameter within a range of0.05 to 1 μm was 0.072 mL/g, and the volume of pores with a porediameter within a range of 1 to 10 μm was 0.001 mL/g.

Mean side crushing strength of this catalyst D was 4.7 kg.

[Hydrocracking Reaction Using Catalyst A and Catalyst B]

Evaluation method 1:

Catalyst A was packed in a fixed bed flow-through reactor which has 100milliliters packing volume, and pre-sulfiding was performed therein.Then hydrocracking was performed under reaction conditions of a pressureof 15 MPa, a hydrogen/starting oil feed ratio of 800 NL/L, LHSV=1.36h⁻¹, and reaction temperature of 390, 380, 370 and 360° C. using vacuumgas oil with a density at 15° C. of 0.831 g/mL, initial boiling point of262.9° C., 97.8 wt % fractions with a boiling point of 293° C. orhigher, total sulfur concentration less than 0.001 wt %, total nitrogenconcentration less than 0.0001 wt %, vanadium concentration less than0.0001 wt %, and nickel concentration less than 0.0001 wt %. When thereaction temperature needed to convert the fractions with a boilingpoint of 293° C. or higher at a conversion rate of 60 wt % and themiddle distillate yield within a boiling point range of 127 to 293° C.at this conversion rate were determined, they were 376.4° C. and 39.9 wt%, respectively.

Catalyst B was similarly packed in the reactor and a hydrocrackingreaction was performed under the same conditions as described above.When the reaction temperature needed to convert the fraction with aboiling point of 293° C. or higher at a conversion rate of 60 wt % andthe middle distillate yield within a boiling point range of 127 to 293°C. at this conversion rate were determined, they were 367.7° C. and 40.3wt %, respectively.

Evaluation Method 2:

Moreover, catalyst A was evaluated as follows under conditions that weredifferent from those described above. Catalyst A was packed in theabove-mentioned fixed-bed flow-through reactor and hydrocracking wasperformed under reaction conditions of a pressure of 15 MPa, ahydrogen/starting oil feed ratio of 800 NL/L, an LHSV=1.36 h⁻¹, and areaction temperature of 380° C. When the conversion rate of fractionswith a boiling point of 293° C. or higher and middle distillate yieldwithin a boiling point range of 127 to 293° C. were determined, theywere 64.5 wt % and 64.4 wt %, respectively.

Catalyst B was packed in the above-mentioned fixed-bed flow-throughreactor, and hydrocracking was performed therein under reactionconditions of a pressure of 15 MPa, a hydrogen/starting oil feed ratioof 800 NL/L, an LHSV=1.36 h⁻¹, and a reaction temperature of 380° C.When the conversion rate of fractions with boiling point of 293° C. orhigher and middle distillate yield within a boiling point range of 127to 293° C. were determined, they were 79.2 wt % and 48.9 wt %,respectively.

[Hydrocracking Using Catalyst C and Catalyst D]

Evaluation method 1:

Catalyst A was packed in a fixed bed flow-through reactor with 100milliliters packing volume, and pre-sulfiding was performed therein.Then hydrocracking with performed under reaction conditions of apressure of 15 MPa, a hydrogen/starting oil feed ratio of 1,000 NL/L,LHSV=1.36 h⁻¹, and reaction temperature of 420, 410, and 400° C. usingvacuum gas oil with a density at 15° C. of 0.9060 g/mL, initial boilingpoint of 309.3° C., 91.3 wt % fractions with a boiling point of 360° C.or higher, total sulfur concentration 0.46 wt %, total nitrogenconcentration 0.081 wt %, vanadium concentration less than 0.0001 wt %,and nickel concentration less than 0.0001 wt %. When the reactiontemperature needed to convert the fraction with a boiling point of 360°C. or higher at a conversion rate of 60 wt % and the middle distillateyield within a boiling point range of 127 to 360° C. at this conversionrate were determined, they were 410.0° C. and 41.2 wt %, respectively.

Catalyst D was similarly packed in the reactor and a hydrocrackingreaction was performed under the same conditions as described above.When the reaction temperature needed to convert the fraction with aboiling point of 360° C. or higher at a conversion rate of 60 wt % andthe middle distillate yield within a boiling point range of 127 to 360°C. at this conversion rate were determined, they were 411.9° C. and 45.6wt %, respectively.

Evaluation Method 2:

Moreover, catalysts C and D were evaluated as follows under conditionsthat were different from those described above.

Catalyst C was packed in the above-mentioned fixed-bed flow-throughreactor and hydrocracking was performed under reaction conditions of apressure of 15 MPa, a hydrogen/starting oil feed ratio of 1,000 NL/L, anLHSV=1.36 h⁻¹, and a reaction temperature of 400° C. When the conversionrate of fractions with a boiling point of 360° C. or higher and middledistillate yield within a boiling point range of 127 to 360° C. weredetermined, they were 40.9 wt % and 72.4 wt %, respectively.

Moreover, catalyst D was packed in the above-mentioned fixed-bedflow-through reactor and hydrocracking was performed under reactionconditions of a pressure of 15 MPa, a hydrogen/starting oil feed ratioof 1,000 NL/L, an LHSV=1.36 h⁻¹, and a reaction temperature of 400° C.When the conversion rate of fractions with a boiling point of 360° C. orhigher and middle distillate yield within a boiling point range of 127to 360° C. were determined, they were 39.4 wt % and 81.3 wt %,respectively.

Comparative Example

[Catalyst E]

As will be described below, catalyst E consisting of 11.0 wt % W, 1.0 wt% Ni, 67.9 wt % silica-alumina, 17.0 wt % alumina was prepared.

First, 1,137 g silica-alumina powder (silica/alumina molar ratio of 4.1,34.4 wt % of which was powder of particle aggregates with a diameter of1 to 10 μm, ignition loss of 23.9 wt %), and 296 g pseudo-boehmitepowder (ignition loss of 27.0 wt %) were kneaded while being mixed, andshaped into a cylindrical shape by extrusion from a round opening with adiameter of 1.6 mm. Then a carrier of a silica-alumina/alumina mixturewas prepared by drying this shaped article for 15 hours at 130° C. andfiring for 1 hour at 600° C. under an air flow. The mean side crushingstrength of this carrier was 2.1 kg. The carrier was impregnated byspraying with an aqueous ammonium metatungstate solution and dried for15 hours at 130° C. Then it was impregnated by spraying with an aqueousnickel nitrate solution and dried for 15 hours at 130° C. Next, it wasfired for 30 minutes at 500° C. under an air flow. Catalyst E wasthereby obtained.

When the pore properties of this catalyst E were measured by nitrogengas adsorption, the volume of pores with a pore diameter within a rangeof 40 to 100 Å was 0.442 mL/g and the median pore diameter was 62 Å.Moreover, as a result of determining pore properties of catalyst E bymercury intrusion porosimetry, the volume of pores with a pore diameterwithin a range of 0.05 to 0.5 μm was 0.026 mL/g, and the volume of poreswith a pore diameter of 0.5 μm to 10 μm was 0.105 mL/g. Furthermore, thevolume of pores with a pore diameter within a range of 0.05 to 1 μm was0.053 mL/g, and the volume of pores with a pore diameter within a rangeof 1 to 10 μm was 0.078 mL/g.

The pore properties of catalyst E are shown by line E in FIG. 1. As withcatalyst A, a sharp peak is seen within a pore diameter range of 40 to100 Å (mesopores). Nevertheless, in contrast to catalysts A and B, thepeak of the macropores appears in the range where pore diameter exceeds1 μm.

Mean side crushing strength of this catalyst A was 3.2 kg.

[Hydrocracking Reaction Using Catalyst E]

Evaluation method 1:

Catalyst E were packed in a fixed bed flow-through reactor with 100milliliters packing volume, and hydrocracking was performed therein aswith catalysts A and B. When the reaction temperature needed to convertthe fraction with a boiling point of 293° C. or higher at a conversionrate of 60 wt % and the middle distillate yield within a boiling pointrange of 127 to 293° C. at this conversion rate were determined, theywere 378.8° C. and 37.0 wt %, respectively.

Evaluation Method 2:

Catalyst E was packed in a fixed-bed flow-through reactor with acatalyst packing volume of 100 ml, and hydrocracking was performedtherein under the same conditions as evaluation method 2 used forcatalyst A. When the conversion rate of fraction with a boiling point of293° C. or higher and middle distillate yield within a boiling pointrange of 127 to 293° C. were found, they were 59.6 wt % and 61.0 wt %,respectively.

The determination devices and methods used in the above-mentionedexamples and comparative examples are listed below:

[Method of Determining Particle Diameter Distribution of ParticleAggregates]

Particle diameter distribution of particle aggregates was determinedusing the MICROTRAC particle diameter analyzer made by Nikkiso Co., Ltd.This involved dispersing powder in water and irradiating laser lightonto the groups of particle aggregates flowing through the water inorder to analyze their particle diameter distribution based on theforward-scattered light.

[Method of Determining Pore Properties]

The AutoPore 9200 made by Micromeritics was used to determine poreproperties by mercury intrusion porosimetry. The ASAP 2400 made byMicromeritics was used to determine pore properties by nitrogen gasadsorption.

[Method of Determining Mean Side Crushing Strength]

Side crushing strength was determined for a sample that had beenextrusion shaped into a cylinder, dried and fired using the TH-203CPtablet breaking strength meter made by Toyama Sangyo Co., Ltd. Thedetermination probe had a round tip with a diameter of 5 mm. Theprocedure whereby collapsing strength was measured in the center of theedge of the cylindrical determination sample was repeated 20 times andthe mean value was calculated.

[Definition of Conversion Rate and Middle Distillate Yield]

The conversion rate and middle distillate selectivity, which showactivity of the catalysts in the examples and the comparative examplewere defined as described below:

conversion rate of fractions with boiling point of 293° C. orhigher=(1−(wt % of fractions with boiling point of 293° C. or higher ofproduct oil/wt % of fractions with a boiling point of 293° C. or higherof starting oil)]×100 (wt %)

 conversion rate of fractions with boiling point of 360° C. orhigher=[1−(wt % of fractions with boiling point of 360° C. or higher ofproduct oil/wt % of fractions with a boiling point of 360° C. or higherof starting oil)]×100 (wt %)

middle distillate yield within boiling point range of 127 to 293°C.=[(weight of fractions within a boiling point range of 127 to 293° C.in product)/weight of product excluding hydrogen sulfide andammonia)]×100 (wt %)

middle distillate yield within boiling point range of 127 to 360°C.=[(weight of fraction within boiling point range of 127 to 360°C.)/(weight of product excluding hydrogen sulfide and ammonia)]×100 (wt%)

[Indicators of Cracking Activity and Middle Distillate Selectivity]

The reaction temperature needed to convert the fractions with a boilingpoint of 293° C. or higher at a conversion rate of 60 wt % and themiddle distillate yield within a boiling point range of 127 to 293° C.,which are shown as indicators of cracking activity and middle distillateselectivity of the catalysts of the examples and the comparativeexample, were calculated as described below:

The apparent reaction rate constant at each reaction temperature wascalculated for the reaction whereby the fractions with a boiling pointof 293° C. or higher are converted with the apparent order of reactionin terms of the concentration of fraction with a boiling point of 293°C. or higher being secondary. An Arrhenius plot was drawn and theArrhenius formula was obtained. The reaction temperature needed toconvert the fraction with a boiling point of 293° C. or higher at aconversion rate of 60 wt % was calculated based on the Arrhenius plotthat was obtained. The conversion rate of fraction with a boiling pointof 293° C. or higher from the experimental results at each reactiontemperature was plotted on the axis of abscissas and the middledistillate yield within the boiling point range of 127 to 293° C. wasplotted on the axis of ordinates to obtain an approximation curveshowing the correlation between the conversion rate and the middledistillate yield. The middle distillate yield within a boiling pointrange of 127 to 293° C. when the conversion rate of the fraction with aboiling point of 293° C. or higher was 60 wt % was calculated from thisapproximation curve.

The reaction temperature needed to convert the fractions with a boilingpoint of 360° C. or higher at a conversion rate of 60 wt % and themiddle distillate yield within a boiling point range of 127 to 360° C.at this conversion rate were calculated as described below:

The apparent reaction rate constant at each reaction temperature wascalculated for the reaction whereby the fractions with a boiling pointof 360° C. or higher are converted with the apparent order of thereaction in terms of the concentration of the fraction with a boilingpoint of 360° C. or higher being secondary, and an Arrhenius plot wasmade and the Arrhenius formula was obtained. The reaction temperatureneeded to convert the fractions with a boiling point of 360° C. orhigher at a conversion rate of 60 wt % was calculated based on theArrhenius formula that was obtained. The conversion rate of fractionswith a boiling point of 293° C. or higher from the experimental resultsat each reaction temperature was plotted on the axis of abscissas, whilethe middle distillate yield of the boiling point range of 127 to 360° C.was plotted on the axis of ordinate to obtain an approximation curveshowing the correlation between the conversion rate and the middledistillate yield. The middle distillate yield of the boiling point rangeof 127 to 360° C. when the conversion rate of fraction with a boilingpoint of 360° C. or higher was 60 wt % was calculated.

Industrial Applicability

The hydrocracking catalyst of the present invention has a specific porestructure of both mesopores and macropores and therefore is sufficientlystrong mechanically. At the same time, excellent hydrocrackingperformance is realized and efficient hydrocracking is possible withrespect to hydrocarbon oils containing 80 wt % or more of a fractionwith a boiling point of, for instance, 250° C. or higher, particularlyvacuum gas oil.

What is claimed is:
 1. A hydrocracking catalyst comprising: a carrierhaving particles of an inorganic oxide and a binder component presentbetween the particles; and at least one metal component supported on thecarrier and selected from Group 6, Group 9, and Group 10 of the PeriodicTable, wherein the median pore diameter of the catalyst is 40 to 100 Åand the volume of pores having a pore diameter within a range of 40 to100 Å ranges from 0.15 to 0.6 mL/g, and the volume of pores of thecatalyst with a pore diameter within a range of 0.05 to 0.5 μm rangesfrom 0.05 to 0.13 mL/g and the volume of pores with a pore diameterwithin a range of 0.5 to 10 μm is less than 0.01 mL/g.
 2. Ahydrocracking catalyst according to claim 1, wherein the inorganic oxideis made up of at least one inorganic oxide selected from the groupconsisting of silica-alumina, silica-titania, silica-zirconia,silica-magnesia, silica-alumina-titania, and silica-alumina-zirconia. 3.A hydrocracking catalyst according to claim 1, wherein the inorganicoxide is comprised of at least one inorganic oxide selected from thegroup consisting of silica-alumina, silica-titania, silica-zirconia,silica-magnesia, silica-alumina-titania, and silica-alumina-zirconia;and USY zeolite.
 4. A hydrocracking catalyst according to any one ofclaims 1 to 3, wherein the binder component comprises at least one ofalumina and boria-alumina.
 5. A hydrocracking catalyst according to anyone of claims 1 to 3, wherein the diameter of at least 60% of theparticles of the inorganic oxide is 10 μm or less.
 6. A hydrocrackingcatalyst according to claim 1, which is used for hydrocrackinghydrocarbon oils containing 80 wt % or more of fractions with a boilingpoint of 250° C. or higher.
 7. A hydrocracking catalyst according toclaim 1 or claim 6, which is used for hydrocracking hydrocarbon oilwhose vanadium and nickel contents are both 0.0005 wt % or less.
 8. Ahydrocracking catalyst according to claim 7, wherein said hydrocarbonoil is vacuum gas oil and the vanadium content and nickel content of thevacuum gas oil are both 0.0001 wt % or less.
 9. A hydrocracking catalystaccording to claim 1, wherein the median pore diameter of the catalystis in the range of 50 to 85 Å.
 10. A method of producing a hydrocrackingcatalyst, defined in claim 1, comprising the steps of: mixing inorganicoxide powder comprising at least 60 wt % of particle aggregates with adiameter of 10 μm or less and binder; shaping, drying and firing themixture of the powder and binder to form the carrier; and supporting atleast one metal component selected from Group 6, Group 9, and Group 10of the Periodic Table on the carrier.
 11. A method of producing ahydrocracking catalyst according to claim 10, wherein the inorganicoxide powder is made from at least one selected from the groupconsisting of silica-alumina, silica-titania, silica-zirconia,silica-magnesia, silica-alumina-titania, and silica-alumina-zirconia.12. A method of producing a hydrocracking catalyst according to claim10, wherein the inorganic oxide powder is made from at least oneselected from the group consisting of silica-alumina, silica-titania,silica-zirconia, silica-magnesia, silica-alumina-titania, andsilica-alumina-zirconia; and USY zeolite.
 13. A method of producing ahydrocracking catalyst according to any one of claims 10 to 12, whereinthe binder component is made from at least one of hydrated aluminiumoxide and boria-containing hydrated aluminium oxide.
 14. A method ofproducing a hydrocracking catalyst according to any one of claims 10 to12, wherein the median pore diameter of the inorganic oxide powderranges from 35 to 100 Å.
 15. A method of hydrocracking hydrocarbon oilscomprising contacting said hydrocarbon oils under hydrocrackingconditions with the hydrocracking catalyst defined in claim 1 in thepresence of hydrogen.
 16. A hydrocracking method according to claim 15,characterized in that the hydrocarbon oil is hydrocarbon oil containing80 wt % or more of fractions with a boiling point of 250° C. or higher.17. A hydrocracking method according to claim 15 or 16, wherein thevanadium content and nickel content of the hydrocarbon oil are both0.0005 wt % or lower.
 18. A hydrocracking method according to claim 17,wherein the hydrocarbon oil is vacuum gas oil and the vanadium contentand nickel content contained in the vacuum gas oil are both 0.0001 wt %or less.